Pipetting device for tissue culture dissemination



R. J. REEDY Aug. 26, 1969 PIPETTING DEVICE FOR TISSUE CULTUREDISSEMINATION Filed June 21. 1967 INVENTOR ROBERT J. REEDY ,ZMMZ

ATTORNEY United States Patent 3,463,013 PIPE'ITING DEVICE FOR TISSUECULTURE DISSEMINATION Robert J. Reedy, Silver Spring, Md., assiguor tothe United States of America as represented by the Secretary of theDepartment of Health, Education, and Welfare Filed June 21, 1967, Ser.No. 647,683 Int. Cl. G01n 1/14 U.S. Cl. 73-425.6 6 Claims ABSTRACT OFTHE DISCLOSURE The present disclosure relates to a hand-operatedpipetting device utilizing sources of superatmospheric pressure andvacuum, which device is particularly suitable in tissue culturedissemination. The device is adapted to receive a pipette and resultantcombination is then operated to aspirate a tissue culture into thepipette by means of the source of vacuum, and then for ejecting thepreviously aspirated culture from the pipette into a suitable flask byuse of the source of air pressure. Vigorous splashing of the cellsuspension breaks up the clumps into smaller units, thereby creatingconditions of greater tissue.

The present invention relates to a hand-controlled pipetting device and,more particularly, to such a device for use in the dissemination oftissue culture.

Until the present time the most common pipetting technique stillconventionally used in most laboratories has involved mouth-pipetting.The unsatisfactory features of mouth-pipetting have been long known,particularly the danger to the operator, the slowness of the operation,and the lack of sanitary conditions, and accordingly, many substitutesfor the common mouth pipette have been suggested. Generally, however,except for the use of a rubber bulb or syringe in conjunction with apipette which has found some acceptability, the various proposals havenot been generally adopted and have been, for one reason or another,unsatisfactory. Furthermore, the previous pipetting techniques have notbeen entirely satisfactory for the dissemination of tissue culture sinceit is desirable to break up the tissue into the smallest possibleparticles and the generally used pipetting techniques have notaccomplished this desired result.

Accordingly, it is an object of the present invention to obviate thedeficiencies of the prior art, such as indicated above.

It is another object of the present invention to provide a hand-operatedpipetting device of improved utility.

It is another object of the present invention to improve the speed ofpipetting, improve the conditions of sanitation associated withpipetting, and to safeguard the technician who is carrying out thepipetting.

It is another object of the present invention to effect tissue culturepipetting while simultaneously breaking up the tissue clumps intosmaller units.

It is another object of the present invention to provide a pipettingdevice which can be easily hand-held and operated with one hand whichwill accomplish the above objects.

These and other objects and the nature and advantages of the presentinvention will be more apparent from the accompanying drawing, wherein:

FIG. 1 is a perspective view, partly broken away, of a pipetting devicein accordance with the present invention.

A pipetting device shown generally at 10, comprises a body member 12having a generally elongated axial bore 14 therein having an outer end16 and an inner end 18. The bore 14 is adapted to receive the open end20 of a conventional pipette 22.

3,463,013 Patented Aug. 26, 1969 In order to provide an air-tight sealbetween the outer wall of the pipette 22 and the inner wall of the bore14, it is generally desirable to utilize some type of sealing means suchas the gasket 24, which is preferably formed of synthetic rubber, suchas neoprene. Other types of seals may also be used and it may bedesirable to utilize an O-ring which Will fit between the outer wallsurface of the pipette 22 and the inner wall surface of the bore 14. Thegasket 24 may effect its sealing by abutting against the open end 20 ofthe gasket 22.

The body member 12 is provided with a first air passageway 26 whchcommunicates with the bore 14 at one end and is connected at the otherend with a suitable source of vacuum through conventional means such asa rubber or plastic hose 28. Disposed along the length of the firstpassageway 26 is a first valve (not shown) carried within a valvehousing 30.

The valve within the valve housing 30 is biased to maintain thepassageway 26 closed. In order to open the valve within the housing 30,it is necessary to merely depress a suitable valve control element 32,which projects outside the housing 30, to effect the opening of thepassageway 26.

The body member 12 is provided with a second air passageway 36 Whichalso communicates With the bore 14 and is connected at its opposite endto a suitable source of air under superatmospheric pressure via a hose38. As with the first passageway 26, the second passageway 36 isprovided along its length with a valve carried Within the valve housing40 and operable with a valve control element 42, which projects outsidethe housing, used to open the valve, thereby opening the passageway 36by merely depressing the valve control element 42.

The precise structure of the valves carried within the housings 30 and40 is not the subject of the present invention and any suitable valvemechanisms may be used, such mechanisms being well known and availablecommercially. It is only necessary that such valves be biased to theclosed position and that they be preferably operated by depressing thevalve control elements 32 and 42.

It is the desirable feature in accordance with the present inventionthat the valve housings 30 and 40 and the respective projecting controlelements 32 and 42 'be located closely adjacent one another so that asthe device 10 is grasped in one hand, the elements 32 and 42 may beeasily depressed with the fingers of one hand in sequence as desired.

Because air under superatmospheric pressure is used in the operation ofthe device 10 in accordance with the present invention, it is generallydesirable to provide the body member 12 with suitable means to preventthe pipette from being expelled from the bore 14. Such means maycomprise a suitable retaining screw 34 extending from the outer surfaceof the body member 12 to the bore 14. A detachable stainless steel pinor other retaining means may be utilized in place of the retaining screw34.

During use, it is generally desired to place a cotton plug in the bore14 between the end of the pipette 20 and the passageways 26 and 36. Inorder to prevent such cotton plug from being drawn into the passageway26 during the application of vacuum, it is desirable to provide astainless steel screen 44 at the end 18 of the bore 14.

The device 10 may be formed of any suitable material such as highchromium stainless steel, brass, titanium, or plastic materials, such asglass reinforced resins, nylon, polycarbonate resin, acetal resin, orothers.

In the preferred embodiment the device is made of brass and measures 3/2 x 1 /2 inches. The bore 14 is provided to receive a 10 ml. pipettefor aseptic introduction into a tissue culture flask. The passageways 26and 36 at their extreme outer ends are provided with suitable fittings26 and 36', respectively, for attachment of /s inch gum rubber hoses 28and 38. Preferably, a source of air pressure of about 5-8 pounds persquare inch is attached to the rubber hose 38 and a vacuum of about 5pounds per square inch is attached to the rubber hose 28. However,greater or lesser amounts of pressure and vacuum can be used accordingto the dexterity of the operator.

The device may be operated as follows:

The entire apparatus, including the hoses, may be first sterilized, suchas by autoclaving, prior to use thereof. A sterile ml. pipette isinserted and locked into the device utilizing the set screw 34. Therubber hoses are connected to a suitable superatmospheric air and vacuumsupply and properly adjusted to an air pressure of about 8 pounds persquare inch and a vacuum of about 5 pounds per square inch. The pipetteis aseptically introduced into a previously prepared tissue cultureflask containing cells which are to be dispersed and broken up intoindividual cell units. The operator, holding the device 10 in one hand,merely depresses the vacuum valve control element 32, thereby drawingabout 5-6 ml. of suspension into the pipette. The operator immediatelyreleases the vacuum valve control element 32, thereby causing the vacuumvalve to automatically close, and then depresses the air pressure valvecontrol element 42 and the suspension is forcibly ejected from thepipette into the flask. By moving the pipette around the sides of theflask while the suspension is being expelled, the tissue flakes adheringto the sides of the flask thus may be washed down. Vigorous splashing ofthe cell suspension breaks up the clumps into smaller units, therebycreating conditions of greater tissue dispersion.

What is claimed is:

1. A hand-operated pipetting device for disseminating tissue culturecomprising:

a body member having an elongated cylindrical bore therein for receivingtherein the large open end of a pipette;

means for providing a generally air-tight seal between the outer surfaceof said pipette and the inner surface of the bore of said body member;

first air passageway means communicating with said bore for connectionto a source of vacuum;

first hand-operable valve means including a first valve housing foropening said first passageway for controlling the passage of air fromsaid bore to the source of vacuum, said valve means having a firstcontrol element projecting outside said first valve housing, and saidvalve means being biased in the closed position;

second air passageway means communicating with said bore for connectionto a source of air under superatmospheric pressure; and

second hand-operable valve means including a second valve housing foropening said second passageway for controlling the passage of air fromthe source of superatmospheric air to said bore, said valve means havinga second control element projecting outside said second valve housing,and said valve means being biased in the closed position.

2. A device in accordance with claim 1, wherein said sealing meanscomprises a flexible gasket located within said bore at the large openend of the pipette.

3. A device in accordance with claim 1, further comprising a screen atthe inner end of said bore adjacent the mouth of said passageway means.

4. A device in accordance with claim 1 wherein said valve controlelements are closely adjacent whereby said valve means are both operatedby the fingers of one hand when said body member is grasped to effectoperation of said device.

5. A device in accordance with claim 4 wherein either of saidpassageways are opened by depressing said valve control elements.

6. A device in accordance with claim 1, further comprising means toretain the pipette within the bore of said body member.

References Cited UNITED STATES PATENTS 2,153,105 4/1939 Szecsi 73-425.62,376,231 5/1945 Cohn 73425.4 2,994,349 8/1961 Denos.

S. CLEMENT SWISHER, Primary Examiner

